Shear Stress Analysis of EHL Oil Films Based on Thermal EHL Theory - Effect of Inlet Oil Temperature -

Abstract

Under the same EHL contact conditions as in the traction experiments carried out by Wedeven et al., the authors performed a non-Newtonian thermal EHL analysis. In the present analysis, the lubricating oil was assumed to behave as a Maxwell fluid. Lubricating oil is the automotive traction oil with the viscosity grade of ISO VG32. Input parameters are maximum Hertzian pressure PH=1.5 GPa, entrainment velocity ue=10 m/s, slide-roll ratio ∑=0%∼4.0% and inlet oil temperature t0=313 K∼413 K. The Eyring stress, the elastic shear modulus and the limiting shear stress which are needed to calculate the shear stress components were obtained from reference traction curves. The traction coefficients obtained by the numerical analysis agreed well with the measured values in traction experiments. Furthermore, it was found that the shear stress distribution is affected not only by the inlet oil temperature but also by the rolling-sliding conditions.

Keywords

• shear stress
• traction oil
• thermal ehl
• maxwell model
• inlet oil temperature
• slide-roll ratio